Apparatus and method for reducing the incidence of sudden stoppage with self balancing skateboards

ABSTRACT

An apparatus and method for reducing the incidence of sudden stoppage while riding a self balancing skateboard. Wheels are mounted with the front of the bumper, or integrated within a special replacement bumper, of the skateboard to provide a low-friction “rollout” instead of an instant stop, allowing the rider to maintain control in the event that the front of the board contacts the ground. The wheels protrude from a lower surface of the bumper to limit contact of the bumper with the ground.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of U.S. provisional application No. 62/649,820, filed Mar. 29, 2018, the contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to self balancing skateboards, and more particularly to safety enhancements for such skateboards.

Self balancing skateboards are inherently dangerous to operate, in part because one end may contact the ground if the motor is not able to provide enough power to balance the rider. These skateboards are usually most dangerous when the forward-facing end contacts the ground, causing very high friction and a corresponding fast stop of the self balancing skateboard. This often results in the rider falling off from the extreme deceleration that occurs.

A self balancing skateboard will often strike the ground through the normal course of riding from varying undulations, holes, or rises in the riding surface. It may also contact the ground in a motor-cutout event, such as when the motor fails from an over-current or low-battery situation.

The forward-facing end of the self balancing skateboard is generally comprised of a hard plastic bumper or metal rail. This bumper has a high coefficient of friction, and therefore may stop the skateboard suddenly when the bumper contacts the ground. The sudden deceleration that results often throws the rider off the skateboard, with resultant injuries.

As can be seen, there is a need for an apparatus and method for providing a low-friction “rollout” instead of an instant stop, allowing the rider to maintain control in the event that the front of the board contacts the ground while in motion.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a self balancing skateboard is disclosed. The skateboard includes a left and a right rail. A platform for supporting a rider is attached to the left and the right rail. A drive wheel and motor assembly, generally consisting of an electric hub motor, is supported on a shaft extending between the left and the right rail. A bumper is attached to a forward end of the platform and rail. A wheel assembly rotationally supports a ground wheel below a bottom surface of the forward bumper.

In some embodiments, the wheel assembly includes a carriage having a pair of lobes protruding from a base of the carriage. The lobes are dimensioned to receive the ground wheel between the lobes and an interior cavity defined within the base of the carriage. Axially aligned apertures are defined in the lobes to receive a wheel axel. The wheel assembly may also include a threaded shaft extending from a top end of the carriage. The threaded shaft is dimensioned to be received through a mounting hole of the forward bumper of the skateboard and threadingly received in a threaded bore defined at a forward end of the platform.

In some embodiments, a void is defined in a bottom surface of the bumper and the carriage of the wheel assemblies are received in the void such that the wheel protrudes from a bottom edge surface of the bumper. In a preferred embodiment, the wheel assembly is mounted at a left and a right lateral aspect of the void. In other embodiments, the wheel assembly is carried within a void defined in the lateral margin of a lower surface of the forward bumper. In yet other embodiments, the wheel assembly is integrally formed with the bumper assembly. The wheel may extend through an aperture opening into the void.

In other aspects of the invention, a wheel assembly is adapted to mount a bumper assembly to a self balancing skateboard. The wheel assembly includes a carriage having a pair of lobes protruding from a base of the carriage. The lobes are dimensioned to receive the ground wheel between the lobes and an interior cavity defined within the base of the carriage. Axially aligned apertures are defined in the lobes to receive a wheel axel. A threaded shaft extends from a top end of the carriage. The threaded shaft is dimensioned to be received through a mounting hole of the bumper assembly of the skateboard and threadingly received in a threaded bore defined at a forward end of the self balancing skateboard. A wheel may be rotationally carried on the wheel axel. A bearing may rotationally support the wheel on the axel.

In yet other aspects of the invention, a bumper assembly for a self balancing skateboard is also disclosed. The bumper assembly includes a bumper configured to be attached to a forward end of a platform and a rail of the self balancing skateboard. A wheel assembly is received in a concavity defined at the lateral margins of a bottom surface of the bumper. The concavity rotationally supports a ground wheel protruding from the concavity below a bottom surface of the bumper.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wheel assembly for a self balancing skateboard;

FIG. 2 is a front elevation view of a wheel assembly for a self balancing skateboard;

FIG. 3A is a top plan view of the wheel assembly;

FIG. 3B is a left side elevation view of the wheel assembly;

FIG. 3C is a front elevation view of the wheel assembly;

FIG. 3D is a right side elevation view of the wheel assembly;

FIG. 3E is a left front perspective view of the wheel assembly;

FIG. 3F is a top plan view of the wheel assembly;

FIG. 3G is a right front perspective view of the wheel assembly;

FIG. 4 is a right side elevation view of a self balancing skateboard provisioned with a wheel assembly;

FIG. 5 is a bottom perspective view showing the wheel assembly mounted in a center recess bumper assembly of a self balancing skateboard;

FIG. 6 illustrates a stopping hazard of conventional self balancing skateboard;

FIG. 7 illustrates the wheel assembly in use with a self balancing skateboard;

FIG. 8 shows an alternative embodiment of a wheel assembly and bumper assembly;

FIG. 9 is a right side elevation view of a self balancing skateboard and the alternative embodiment of the bumper assembly;

FIG. 10A is a bottom plan view of an alternative bumper assembly with integrated wheel assembly;

FIG. 10B is a Front elevation view of the bumper assembly with integrated wheel assembly; and

FIG. 10C is a bottom front perspective view of the bumper assembly with integrated wheel assembly.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

Broadly, embodiments of the present invention an apparatus and method for providing a low-friction “rollout” for a self balancing skateboard instead of an instant stop, allowing the rider to maintain control in the event that the front of the board contacts the ground. As seen in reference to the drawings of FIGS. 1 and 2, aspects of the invention include a wheel assembly 12 that operatively couples with a bumper assembly 18 of a self balancing skateboard 11. The self balancing skateboard 11 includes a center drive wheel and motor assembly 10 that is electronically controlled to provide a self-balanced skateboard platform 20. The center drive wheel and motor assembly 10 and platform 20 are supported by a left and a right side rail 14.

A front 18 and a rear bumper 16 are disposed at between the rails 14 and are attached to the platform 20 and rails 14. The bumpers 16, 18 on the self balancing skateboard 11 protect the board 11 from damage, but do nothing to help the user maintain control if the bumpers 16, 18 contact the ground G.

The wheel assembly 12 according to aspects of the invention include a carriage 1 having a pair of lobes protruding from a base of the carriage 1. The lobes are dimensioned to receive a ground wheel 4 between the lobes and an interior cavity defined within the base. Axially aligned apertures are defined in the lobes to receive a wheel axel 2. The wheel 4 may include a bearing 5 to rotationally carry the wheel 4 on the axel 2. Shims 6 may be provided to space the wheel 4 between the lobes. The axel 2 may be secured with a threaded fastener 3 or internal threads in one of the axially aligned apertures.

The carriage 1 includes a threaded shaft 7 extending from a top end of the carriage 1. The threaded shaft 7 is dimensioned to be received through a mounting hole of the forward bumper 18 of the skateboard 11 and threadingly received in a threaded bore defined at a forward end of the platform 20. In a first embodiment, shown in reference to FIG. 5, the forward bumper 18 includes a void 22 defined in a bottom surface of the bumper. The carriage 1 of the wheel assemblies are received in the void 22 such that the wheel 4 protrudes from a bottom edge surface of the bumper 18. A wheel assembly 12 is mounted to the left and right lateral aspects of the void 22.

In the embodiment shown in reference to FIGS. 8 and 9, the wheel assembly 12 is carried within a void defined in the lateral aspects of the forward bumper 18. In this instance, the wheel assembly 12 may be integrally formed with the bumper so as to avoid the threaded shaft 7 for mounting the wheel assembly to the bumper 18. The wheel 4 extends through an aperture 23 opening into the void.

As seen in reference to FIGS. 6 and 7, the wheel assemblies 12 and associated ground wheels 4 mounted on the front of the bumper 18, or integrated within the alternative bumper, provide a low-friction “rollout” instead of an instant stop, allowing the rider to maintain control in the event that the front bumper 16 of the board 11 contacts the ground G.

The carriage 1 may be made of plastics using injection molding, 3D printed, or formed with metal casting or metal milling technologies, is created to hold a wheel 4 of a suitable size. The wheel assemblies 12 are then attached to the bumper 18 at the forward end of the self balancing skateboard 11 using screws, glue, or a specially made bumper that accepts the carriage 1. Wheels 4 with low friction ball bearings 5 are added and secured using various screws and nuts to secure the wheel 4 in place.

In another embodiment, three or more wheels may be used instead of two. In another embodiment, a bumper 24 with integrated wheels 4, such as shown in FIGS. 10A-10C, may replace the stock bumper of the skateboard 11, and allow for direct installation of the wheels 4 into concavities 26 formed into the bumper 24. In this instance the concavities 26 are shaped to receive the wheels 4 therein. The concavities 26 are formed in the lateral margins of a lower surface of the bumper 24. The bumper 24 has a plurality of apertures 28 that are defined to align with the threaded mounting bores of the platform 20 and rails 14 of the self balancing skateboard 11.

To use this invention, a rider would install the wheel assembliess 12 onto their self balancing skateboard 11 on the forward (in terms of direction of travel) end using simple hand tools like an Allen key or screwdriver. The rider then rides as usual, and if the nose happens to touch down on the ground, the wheels 4 reduce friction enough to keep the rider from being thrown off the board 11.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 

What is claimed is:
 1. A self balancing skateboard, comprising: a left and a right rail; a platform for supporting a rider attached to the left and the right rail; a drive wheel and a hub motor assembly supported on a shaft extending between the left and the right rail; a bumper attached to a forward end of the platform and rail; and a wheel assembly rotationally supporting a ground wheel below a bottom surface of the bumper.
 2. The self balancing skateboard of claim 1, wherein the wheel assembly further comprises: a carriage having a pair of lobes protruding from a base of the carriage, the lobes dimensioned to receive the ground wheel between the lobes and an interior cavity defined within the base; and axially aligned apertures defined in the lobes to receive a wheel axel.
 3. The self balancing skateboard of claim 2, wherein the wheel assembly further comprises: a threaded shaft extending from a top end of the carriage, the threaded shaft dimensioned to be received through a mounting hole of the forward bumper of the skateboard and threadingly received in a threaded bore defined at a forward end of the platform.
 4. The self balancing skateboard of claim 3, further comprising: a void defined in a bottom surface of the bumper; and the carriage of the wheel assemblies are received in the void such that the wheel protrudes from a bottom edge surface of the bumper proximal to the void.
 5. The self balancing skateboard of claim 4, wherein the wheel assembly is mounted to a left and a right lateral aspect of the void.
 6. The self balancing skateboard of claim 4, further comprising: the wheel assembly is carried within a void defined in the lateral aspects of the forward bumper.
 7. The self balancing skateboard of claim 6, wherein the wheel assembly is integrally formed with the bumper assembly.
 8. The self balancing skateboard of claim 7, wherein the wheel extends through an aperture opening into the void.
 9. A wheel assembly adapted to mount a bumper assembly to a self balancing skateboard, comprising: a carriage having a pair of lobes protruding from a base of the carriage, the lobes dimensioned to receive the ground wheel between the lobes and an interior cavity defined within the base of the carriage; axially aligned apertures defined in the lobes to receive a wheel axel; and a threaded shaft extending from a top end of the carriage, the threaded shaft dimensioned to be received through a mounting hole of the forward bumper of the skateboard and threadingly received in a threaded bore defined at a forward end of the self balancing skateboard.
 10. The wheel assembly of claim 9, further comprising: a wheel rotationally carried on the wheel axel.
 11. The wheel assembly of claim 10, further comprising: a bearing rotationally supporting the wheel on the axel.
 12. A bumper assembly for a self balancing skateboard, comprising; a bumper configured to be attached to a forward end of the platform and a rail of the self balancing skateboard; and a wheel assembly received in a concavity defined at the lateral margins of a bottom surface of the bumper, the concavity rotationally supporting a ground wheel protruding from the concavity below a bottom surface of the bumper. 